The present invention(s) relates to spinal rods capable of expansion for treating a variety of spinal maladies.
A scoliotic spine is one in which the spinal column is abnormally curved in one or more different directions, causing resultant adverse side effects for the person suffering from the deformity. Surgeons have attempted to correct this abnormal curvature, in some cases, with spinal rods implanted on the patient's spinal column. The spinal rods exert a force on the spinal column to correct and restore the natural curvature thereof. Pediatric scoliosis is a particular spinal deformity that is marred with a common issue—the patient is young and growing and, consequently, the patient's spinal column is growing as well. Thus, any effort to straighten the young patient's spinal column with, for example, a fixed-length rod is likely to encounter a problem. Namely, as the spine grows the fixed-length rod does not allow further thoracic growth in the patient. As a result, expandable spinal rods have developed to accommodate the growing spine in pediatric patients.
Examples of existing expandable spinal rods include magnetic growing spinal rods and mechanically distractible spinal rods. In the case of magnet growing spinal rods, some include a motor actuated by an external magnet to cause separate rod portions to distract and, consequently, lengthen the overall spinal rod. Mechanically distractible spinal rods typically have rod portions that are manually movable relative to each other via a distraction instrument. The rod portions are distracted during multiple different surgeries to cause lengthening of the overall spinal rod and correction of the underlying deformity. Magnetic growing rods suffer from a number of defects, however, namely distraction forces are limited by the strength of the motor used therewith. In addition, the overall rod is not susceptible to common medical imaging techniques (e.g., magnetic resonance imaging (MRI)) used during surgery. Mechanically-distractible rods also suffer downsides, for example multiple invasive surgical interventions are required after the initial, primary surgery to lengthen the rod (e.g., by use of a distractor instrument). The patient therefore suffers from the side effects of multiple invasive surgeries to correct the spinal deformity.
There is therefore a need for an improved spinal rod device usable to correct, for example, scoliosis of the spine.